UST912001I4

ABSTRACT

DISCLOSED IS A PROCESS FOR POWDER COATING ELECTRICALLY NONCONDUCTIVE SUBSTRATE WHICH CAN WITHSTAND A TEMPERATURE WITHIN THE RANGE OF ABOUT 375*F. TO ABOUT 500*F. WITHOUT DEFORMING, CHARRING, AND THE LIKE IN SELECTED AREAS. SUITABLE SUBSTRATES ARE FABRICS, PAPER PRODUCTS, GLASS, CERAMICS, THERMOSETTING RESINS SUCH AS PHENOLICS, UREAFORMALDEHYDE AND UREAMELAMINE RESINS, THERMOSETTING POLYESTER AND CRYSTALLINE LINEAR POLYESTERS SUCH AS POLYETHYLENE TEREPHTHALATE. IN THIS PROCESS A GROUNDED ELECTRICALLY CONDUCTIVE, SHAPED SUBSTRATE IS POSITIONED ADJACENT ONE SIDE OF A NONCONDUCTIVE, HEATABLE SUBSTRATE. THE OPPOSITE SIDE OF THE NONCONDUCTIVE SUBSTRATE IS THEN CONTACTED WITH CHARGED POLYMER PARTICLES AND THE CHARGED POLYMER PARTICLES ADHERE TO THE ELECTRICALLY NONCONDUCTIVE SUBSTRATE ONLY IN A SELECTED AREA HAVING A SHAPE CORRESPONDING TO THE SHAPE OF THE GROUNDED, ELECTRICALLY CONDUCTIVE SUBSTRATE. THE NONCONDUCTIVE SUBSTRATE HAVING THE POLYMER PARTICLE DEPOSITED THEREON IS THEN HEATED TO FORM THE POLYMER PARTICLE INTO A COATING FUSED TO THE NONCONDUCTIVE SUBSTRATE IN A SHAPE CORRESPONDING TO THE SHAPE OF THE GROUNDED, ELECTRICALLY CONDUCTIVE SUBSTRATE. THE POLYMER PARTICLES CAN BE BE COMPRISED OF CELLULOSE ESTER, POLYOLEFIN, POLYESTER OF MIXTURES THEREOF. IN ONE PARTICULARLY ADVANTAGEOUS EMBODIMENT THE POLYMER CAN BE COMPOSED OF A MIXTURE OF POLY (,4-CYCLOHEXYLENE DIMETHYLENE TEREPHTHALATE/ISOPHTHALATE) AND CELLULOSE ACETATE BUTYRATE.



